Severe Thunderstorm Warning 27, NWS Nashville, TN

Area Forecast Discussion
National Weather Service Nashville TN
704 PM CDT Fri Mar 24 2023

...New AVIATION...

.SHORT TERM...
(This afternoon through Saturday Night)
Issued at 147 PM CDT Fri Mar 24 2023

Showers and a few thunderstorms that initiated along a surface
front near the Ohio River pushed down into Middle Tennessee today.
The rain impacted mainly the northwest half of the area with some
hefty downpours including about 0.74" at Clarksville. The cold
pool with this activity pushed across much of Middle Tennessee
keeping temperatures several degrees lower than expected. It
should be noted we do not think this cooling will have any impact
on the potential for severe storms tonight.

For tonight, there are no major changes to the on-going messaging.
We continue to expect a vigorous QLCS to move west to east across
Middle Tennessee from 9 PM CDT to 3 AM CDT. Cape is not really
impressive with the QLCS outrunning the greatest instability. but
the dynamics of the system will be quite impressive, and CAMs are
showing maintenance of very strong updrafts and pockets of
rotation along the line. Damaging winds continue to be the main
concern. We expect to see some pockets of wind damage with bows
and surges along the line of storms. This vigorous system could
bring some thunderstorm wind gusts pushing 70 mph. There will be a
lot of shear and a narrow window of strong low level helicity, so
tornadoes cannot be ruled out.

We have also issued a Wind Advisory for gradient winds with the
incoming low pressure system. Winds may become quite gusty to 45
or 50 mph an hour or 2 before storms arrive. We are not expecting
a repeat of the March 3rd event with long duration damaging winds.
But, some local pockets of storm damage could be as severe, so
people should prepare for the possibility of downed trees and
power outages.

There will also be very heavy downpours with the storms, but we
think the fast motion of the QLCS will limit the flood potential
to just a few brief flood advisories. We are not expecting major
flood impacts, so no flood watch for now.

The main line of storms should be moving off the Plateau early
Saturday morning. There will be some upper level troughing behind
the storms, so intervals of clouds and sun will be seen Saturday.
Forecast soundings show some fairly steep mid level lase rates and
a little cape, so we are adding slight shower chances for
Saturday. These should be very small, local, fast-moving showers
if they do materialize. Otherwise, somewhat breezy with highs
Saturday around 70.

&&

.LONG TERM...
(Sunday through next Friday)
Issued at 147 PM CDT Fri Mar 24 2023

Sunday looks like a great day with sunshine and lower 70s.
A warm front to our south will bring up small rain chances Sunday
night, then another weak system will bring a few showers Monday
night. After that, temps cool off a little, but really only to
normal levels for this time of year. The next chance of rain and
thunderstorms arrives late week as another upper-level trough
approaches from the west.

&&

.AVIATION...
(00Z TAFS)
Issued at 649 PM CDT Fri Mar 24 2023

Mostly VFR conditions in place right now across all TAF sites, but
low clouds will increase as we go throughout the evening. Expect
MVFR to IFR conditions to develop as a line of storms move over
taf sites from west to east from 03Z at CKV to around 08Z at CSV.
Heavy rain in storms will likely cause visibilities to fall. Also
expect gusty winds, possibly severe with the main part of the
line. Outside of storms, winds will be generally out of the south
with gusts from 10 to 25 knots.

Storms should push east of the area by 09z, but MVFR cigs may
persist through midmorning on Saturday. Improvements to VFR are
expected by late morning to early afternoon. Winds will generally
be out of the west around 10 knots on Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      60  71  47  74 / 100  20  10   0
Clarksville    56  65  44  71 / 100  20  10   0
Crossville     57  69  44  70 / 100  20  10   0
Columbia       58  72  46  74 / 100  20   0   0
Cookeville     59  70  46  71 / 100  20  10   0
Jamestown      58  69  42  70 / 100  20   0   0
Lawrenceburg   59  72  47  74 / 100  20   0   0
Murfreesboro   59  73  46  74 / 100  20   0   0
Waverly        56  66  46  71 / 100  20  10   0

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 7 AM CDT Saturday for Bedford-Cannon-
Cheatham-Clay-Coffee-Cumberland-Davidson-De Kalb-Dickson-
Fentress-Giles-Grundy-Hickman-Houston-Humphreys-Jackson-Lawrence-
Lewis-Macon-Marshall-Maury-Montgomery-Overton-Perry-Pickett-
Putnam-Robertson-Rutherford-Smith-Stewart-Sumner-Trousdale-Van
Buren-Warren-Wayne-White-Williamson-Wilson.

&&

SHORT TERM...13
LONG TERM....13
AVIATION.....Whitehead